Help with math please
 

I need to make a 12 1/2 inch pinwheel (finished 12 inches) and I would like to make it the way Jenny does. Sewing all four sides of a square, cutting diagonally, etc. I don't know how to figure the math out to make the squares the right size. Can someone give me the formula? Math is not my long suit. Thanks in advance for any help you can give me.

I can't help as I am not too long on Math either, but I would like to say Happy 4th and I hope you find your answer!:thumbup:

I don't know if these will help

http://whipup.net/2011/03/17/guest-b...are-triangles/
http://www.pinterest.com/pin/338121884494954329/

This is a great method to make quick HST but please remember that all of your edges will be on the bias, so use starch or be very careful not to stretch when piecing your blocks.
Another thing you can do is cut your original large squares on the bias then the cut edges of your HST units will be on the straight grain.
Using the formula in the link above the squares should be 10.15625, so I would cut them at 10.25 and trim each HST unit to 6.50. When you sew the four HST together you will get a 12.5 inch pinwheel block that will finish at 12 inches. Hope this helps

Will this help? http://blog.missouriquiltco.com/upda...asy-pinwheels/

My friend show this at our sewer's meeting. I do NOT understand why anyone would want to have ALL THOSE BIAS EDGES?? That can be absolutely catastrophic Bias edges are NOT your friend and unless you are experienced, trust me, your block MAY come out wonky. Keep it simple and make the pinwheel with 2 sets of two squares, draw a diagonally line, stitch on each side of the line (HST)and you will have NO bias edges to deal with. I have an older computer so I am not able to watch videos online but to me with 28 years of experience of quilting, this is one of the wackiest ideas I have every heard.

Ack, math! ( This is me, running from the building!)

Thanks everyone. Happy fourth